1. Field of the Invention
The present invention relates to an information recording apparatus or an information recording system which can write information into a CD-R/RW (Compact Disk-Recordable/Rewritable), DVD-R/RW (Digital Versatile Disc-R/RW), magnetic optical disc, magnetic disc (such as a hard disc or a floppy disc), memory card (RAM), or tape and which can be used as a replaceable medium for a computer system. Further, the present invention relates to an information recording medium or a computer readable recording medium that stores a program causing a microcomputer or host to execute software.
2. Description of the Related Art
Generally, this kind of information recording apparatus is used as an external storage device of the host computer, and is connected to the host computer so that an information recording system can be configured. Write information that is to be written to a recording medium in the information recording apparatus is transferred from the host side. There are many cases where the bit rate at which write information is transferred to the information recording apparatus from the host differs from the recording rate at which information is written to the recording medium in the information recording apparatus. Typically, the recording rate at which information is recorded on the recording medium in the information recording apparatus is lower (slower) than the information transfer bit rate.
Therefore, the program on the user or host side is caused to wait at the time of recording data by the information recording apparatus. Particularly, in an information recording apparatus in which it takes a long time to record data, the program executed thereby may be caused to wait and the recording may fail in the end. This problem has become conspicuous in the recent situation in which the information recording apparatus needs a medium having a larger recording capacity.
The recording may fail because of various factors. For example, one factor relates to a situation in which the bit rate of write information from the host is different from the bit rate at which information is actually written. Another factor is involved in a situation in which another information recording apparatus is connected to the same communication path, so that the transfer bit rate cannot be settled. Yet another factor stems from error/bug included in OS or driver.
There are many proposals to cope with situations and problems as described above. These proposals primarily monitor a buffer memory provided in the information recording apparatus and temporarily stops write operation due to monitor results.
For example, Japanese Laid-Open Patent Application No. 2-242326 discloses an information recording apparatus configured as follows. When a given amount of recording data from the host is stored in a buffer, a data write operation from the buffer to a recording medium is started. When the buffer becomes full of recording data from the host, data loading from the host is stopped. When data in the buffer has been written into the recording medium by a given one-write data unit, the data load from the host is restarted.
Also, Japanese Laid-Open Patent Application No. 10-63433 discloses an information recording method and apparatus configured as follows. When data stored in a buffer becomes below a given storage amount, recording of process recording information is stopped within an in-recording recording unit that is a predetermined recording unit in which process recording information that is being recorded on an information recording medium is contained. When the detected amount of data stored in the buffer becomes equal to or greater than the given storage amount, the recording of process recording information on the information recording medium is restarted from the recording unit in which the process recording information to be time-serially recorded before the recording unit in recording is contained.
Further, the above application discloses the following. Particularly, in high-density optical discs, data is recorded in a dispersed fashion. If a xe2x80x9cbuffer under runxe2x80x9d occurs, it would be very difficult to maintain continuity. It is therefore required to monitor the buffer and to temporarily stop recording and restart on the basis of the monitor results. That is, the writing will be interrupted unless write data is supplied by the host at a transfer rate equal to or higher than the recording rate of the information recording apparatus (optical disc drive). In this case, data can be no longer written additionally, so that the writing of data fails. A phenomenon as described above is generally called xe2x80x9cbuffer under runxe2x80x9d.
Taking into consideration the above buffer under run, Japanese Laid-Open Patent Application No. 10-49990 discloses an optical disc drive having the following first and second means (units). The first means is to perform a write operation directed to maintaining data continuity by CIRC (Cross Interleave Read Solomon) demodulation at the beginning and ending of data write with respect to an optical disc. The second means is to temporarily stop the write operation if data transfer from the host is not in time while data is being written to the optical disc and to restart the data write when a sufficient amount of data is transferred from the host. The above two means make it possible to normally reproduce data continuously even after restarting.
Japanese Laid-Open Patent Application No. 2000-40302 discloses a disc recording apparatus configured as follows. Recording of data on a disc is interrupted when a situation in which buffer under run may occur occurs. When the situation in which buffer under run may occur is avoided, recording is restarted from the position that continuous to the last recording data on the disc immediately before the recording is interrupted, so that data can be recorded continuously. The above proposal ensures continuity of recording data on the disc even when buffer under run occurs.
In the temporary stop of recording in any of the above-mentioned conventional manners, the buffer capacity is monitored. When the available buffer capacity becomes small, the recording of data on the recording medium is temporarily stopped and is then restarted automatically. The conventional temporarily stop of recording does not take into account users"" circumstances and operating conditions of other application programs in the computer system (information recording system). For example, these individual factors are not used to temporarily stop recording or allow another job to be executed by interruption. Therefore, the conventional temporarily stop of recording is not flexible. Further, intentional stop of recording is not permitted. The commercial power source is therefore required to always work and supply electricity. A battery cannot be used as power source of the computer system. This leads to a low flexibility of the conventional temporary stop.
It is therefore an object of the present invention to provide an information recording apparatus, information recording system and information recording medium enabling intentional stop and restarting of recording while data can be temporarily stopped and restarted and can be read continuously.
Another object of the present invention is to provide an information recording apparatus, information recording system and information recording medium in which a power supply can be turned OFF in response to temporary stop of recording so that the flexibility of recording can be improved.
Yet another object of the present invention is to provide an information recording apparatus, information recording system and information recording medium which allows another job to be executed by interruption so that the flexibility of recording can be improved.
A further object of the present invention is to provide an information recording apparatus, information recording system and information recording medium which allows the use of a battery as power source so that the portability and flexibility can be improved.
These objects of the present invention are achieved by an information recording apparatus that records information on a recording medium including: a write unit performing a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium; a stop instruction unit instructing a temporary stop of the write operation during the write operation; a restart instruction unit instructing a restart of the write operation; and a write stop/restart control unit controlling the write unit to stop performing the write operation in response to an instruction of the temporary stop by said stop instruction unit and controlling the write unit to restart performing the write operation in response to an instruction of the restart by the restart instruction unit.
The above information recording apparatus is equipped with the write unit that performs a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium. It is therefore possible to continuously reproduce data later even after the write operation is temporary stopped and restarted. In addition, the information recording apparatus includes: a stop instruction unit instructing a temporary stop of the write operation during the write operation; a restart instruction unit instructing a restart of the write operation; and a write stop/restart control unit controlling the write unit to stop performing the write operation in response to an instruction of the temporary stop by said stop instruction unit and controlling the write unit to restart performing the write operation in response to an instruction of the restart by the restart instruction unit. It is therefore possible to intentionally stop and restart the write operation at an arbitrary timing. This makes it possible to intentionally stop information recording on the basis of an operating state of another application program and a user""s specific circumstance. The information recording apparatus thus configured enables highly flexible recording.
The above can be realized by an information recording apparatus that collaborates with a computer readable recording medium for storing a program used in an information recording apparatus that includes a microcomputer and records information on the computer readable recording medium, said program causing the microcomputer to execute the steps of: (a) performing a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium; (b) instructing a temporary stop of the write operation during the write operation; (c) instructing a restart of the write operation; and (d) controlling the step (a) to stop performing the write operation in response to an instruction of the temporary stop by the step (b) and controlling the step (a) to restart performing the write operation in response to an instruction of the restart by the step (c). This program is loaded to a computer so that the above-mentioned information recording apparatus can be implemented.
The information recording apparatus may be configured so that it further includes a saving unit saving information about a state of the write operation obtained at the time of temporarily stopping the write operation of the write unit by the write stop/restart control unit.
Hence, even if the write operation is intentionally stopped at an arbitrary timing, information about the state at that time can be saved in the non-volatile memory. The information is used when the write operation is restarted. Hence, it is possible to realize the write operation so that information is continuous before and after the temporary stop. Even when power supply is turned OFF, the continuity of data can be ensured by using the state information stored in the non-volatile memory.
The above can be realized by the information recording apparatus that collaborates with the above-mentioned recording medium may be configured so that the recording medium further includes a program that causes the microcomputer to execute a step of saving, in a non-volatile memory, information about a state of the write operation obtained at the time of temporarily stopping the write operation by the step (d).
The information recording apparatus may be configured so that it further comprises: an interrupt instruction unit instructing an interrupt process when the write unit is temporarily stopping the write operation; and an interrupt processing unit performing the interrupt process in response to an instruction of the interrupt process by the interrupt instruction unit.
Even if the write operation is intentionally stopped any time, information about the state at that time can be saved in the non-volatile memory. The information is used when the write operation is restarted. Hence, it is possible to realize the write operation so that information is continuous before and after the temporary stop. This allows another job to be executed by interrupt. After the interrupt process is finished, the write operation can be restarted.
The above can be realized by the information recording apparatus that collaborates with a program that causes the microcomputer to execute the steps of: (e) instructing an interrupt process when the write unit is temporarily stopping the write operation; and (f) performing the interrupt process in response to an instruction of the interrupt process by the step (e).
The information recording apparatus may be configured so that the interrupt processing unit comprises a plurality of LSI chips that are arranged in a multiple formation and operate selectively. It is therefore possible to easily realize a structure that causes the microcomputer to handle the interrupt process in a state that the write operation waits for restarting after the temporary stop.
The information recording apparatus may be configured so as to further include a battery as a power source. The information recording apparatus has high resistance to fault resulting from the employment of the mechanism which allows the write operation to be stopped any time. Hence, the battery can be used as a power source, so that the information recording apparatus is highly portable.
The information recording apparatus may be configured so that the stop instruction unit and the restart instruction unit comprise key buttons. Thus, it is easy for the user to intentionally input instructions of temporary stop and restart.
The information recording apparatus may be configured so that it further comprises a detection unit that detects an available capacity that remains in the battery, wherein the stop instruction unit uses a temporary stop signal generated by the detection unit when the available capacity becomes equal to or lower than a predetermined threshold level, and a restoration signal generated by the detection unit when the available capacity is restored. It is therefore possible to make temporary stop before the remaining capacity of the battery becomes short and cause the write operation to wait for restoration.
The above can also be realized by the information recording apparatus which collaborates with a computer readable recording medium that stores a program that causes the microcomputer to execute a step (e) of detecting an available capacity that remains in the battery, wherein the step (b) uses a temporary stop signal generated by the step (e) when the available capacity becomes equal to or lower than a predetermined threshold level, and a restoration signal generated by the step (e) when the available capacity is restored.
The above-mentioned objects of the present invention are also achieved by an information recording system comprising: an information recording apparatus recording information on a recording medium; and a host that transfers the information to the information recording apparatus, a write unit performing a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium; a stop instruction unit instructing a temporary stop of the write operation during the write operation; a restart instruction unit instructing a restart of the write operation; and a write stop/restart control unit controlling the write unit to stop performing the write operation in response to an instruction of the temporary stop by said stop instruction unit and controlling the write unit to restart performing the write operation in response to an instruction of the restart by the restart instruction unit.
The above information recording system is equipped with the write unit that performs a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium. It is therefore possible to continuously reproduce data later even after the write operation is temporary stopped and restarted. In addition, the information recording system includes: a stop instruction unit instructing a temporary stop of the write operation during the write operation; a restart instruction unit instructing a restart of the write operation; and a write stop/restart control unit controlling the write unit to stop performing the write operation in response to an instruction of the temporary stop by said stop instruction unit and controlling the write unit to restart performing the write operation in response to an instruction of the restart by the restart instruction unit. It is therefore possible to intentionally stop and restart the write operation at an arbitrary timing. This makes it possible to intentionally stop information recording on the basis of an operating state of another application program and a user""s specific circumstance. The information recording system thus configured enables highly flexible recording.
The above can also be realized by the information recording system that collaborates with a computer readable recording medium for storing a program used in an information recording system comprising an information recording apparatus recording information on a recording medium, and a host that transfers the information to the information recording apparatus, said program causing the host to execute the steps of: (a) performing a write operation on the recording medium in which data continuity is maintained at an ending and an beginning point of writing information to the recording medium; (b) instructing a temporary stop of the write operation during the write operation; (c) instructing a restart of the write operation; and (d) controlling the step (a) to stop performing the write operation in response to an instruction of the temporary stop by the step (b) and controlling the write unit to restart performing the write operation in response to an instruction of the restart by the step (c).
The information recording system may be configured so that it further comprises a saving unit saving, in a non-volatile memory, information about a state of the write operation obtained at the time of temporarily stopping the write operation of the write unit by the write stop/restart control unit.
Hence, even if the write operation is intentionally stopped at an arbitrary timing, information about the state at that time can be saved in the non-volatile memory. The information is used when the write operation is restarted. Hence, it is possible to realize the write operation so that information is continuous before and after the temporary stop. Even when power supply is turned OFF, the continuity of data can be ensured by using the state information stored in the non-volatile memory.
The above can also be realized by the information recording system that collaborates with a computer readable recording medium that further comprises a program that causes the host to execute a step of saving, in a non-volatile memory, information about a state of the write operation obtained at the time of temporarily stopping the write operation of the write unit by the step (d).
The information recording system may be configured so as to it further comprise: an interrupt instruction unit instructing an interrupt process when the write unit is temporarily stopping the write operation; and an interrupt processing unit performing the interrupt process in response to an instruction of the interrupt process by the interrupt instruction unit.
Even if the write operation is intentionally stopped any time, information about the state at that time can be saved in the non-volatile memory. The information is used when the write operation is restarted. Hence, it is possible to realize the write operation so that information is continuous before and after the temporary stop. This allows another job to be executed by interrupt. After the interrupt process is finished, the write operation can be restarted.
The above can also be realized by the information recording system that collaborates with a computer readable recording medium that further comprises a program that causes the host to execute a step (e) of detecting an available capacity that remains in the battery, wherein the step (b) uses a temporary stop signal generated by the step (e) when the available capacity becomes equal to or lower than a predetermined threshold level, and a restoration signal generated by the step (e) when the available capacity is restored.
The information recording system may be configured so that the stop instruction unit and the restart instruction unit comprise key buttons. Hence, it is easy for the user to intentionally input the instructions of temporary stop and restart.